As a constant envelope consecutive phase modulation technology, Gaussian Minimum Shift Keying (Gaussian Filtered Minimum Shift Keying, GMSK for short) is widely applied in a Global system for mobile communications (Global System for Mobile Communication, GSM for short).
FIG. 1 is a schematic diagram of a sending principle of a GMSK transmitter. Pilot symbols are inserted before data symbols, or pilot symbols are inserted into data symbols at equal intervals. The pilot symbols are a pseudo random sequence generated by means of pseudo random, and differential coding and GMSK modulation are performed on the data symbols into which the pilot symbols are inserted, to obtain a GMSK modulation signal. FIG. 2 is a schematic diagram of a receiving principle of a GMSK receiver. Matched filtering is performed on a GMSK modulation signal to obtain a data receiving signal and a pilot receiving signal. Channel estimation is performed according to the pilot receiving signal and a pilot symbol that is stored locally in the GMSK receiver and that is consistent with a pilot symbol on a GMSK transmitter side, to estimate a channel coefficient. Equalization processing is performed by using the channel coefficient and the data receiving signal to obtain a data estimation symbol, that is, a data symbol restored by the GMSK receiver.
However, using a pseudo random sequence as a pilot symbol on the GMSK transmitter and the GMSK receiver affects channel estimation accuracy, and causes poor channel estimation performance.